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/*
 * INET		An implementation of the TCP/IP protocol suite for the LINUX
 *		operating system.  INET is implemented using the  BSD Socket
 *		interface as the means of communication with the user level.
 *
 *		PACKET - implements raw packet sockets.
 *
 * Version:	$Id: af_packet.c,v 1.1.1.1 2004-04-15 01:16:52 phoenix Exp $
 *
 * Authors:	Ross Biro, <bir7@leland.Stanford.Edu>
 *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
 *		Alan Cox, <gw4pts@gw4pts.ampr.org>
 *
 * Fixes:	
 *		Alan Cox	:	verify_area() now used correctly
 *		Alan Cox	:	new skbuff lists, look ma no backlogs!
 *		Alan Cox	:	tidied skbuff lists.
 *		Alan Cox	:	Now uses generic datagram routines I
 *					added. Also fixed the peek/read crash
 *					from all old Linux datagram code.
 *		Alan Cox	:	Uses the improved datagram code.
 *		Alan Cox	:	Added NULL's for socket options.
 *		Alan Cox	:	Re-commented the code.
 *		Alan Cox	:	Use new kernel side addressing
 *		Rob Janssen	:	Correct MTU usage.
 *		Dave Platt	:	Counter leaks caused by incorrect
 *					interrupt locking and some slightly
 *					dubious gcc output. Can you read
 *					compiler: it said _VOLATILE_
 *	Richard Kooijman	:	Timestamp fixes.
 *		Alan Cox	:	New buffers. Use sk->mac.raw.
 *		Alan Cox	:	sendmsg/recvmsg support.
 *		Alan Cox	:	Protocol setting support
 *	Alexey Kuznetsov	:	Untied from IPv4 stack.
 *	Cyrus Durgin		:	Fixed kerneld for kmod.
 *	Michal Ostrowski        :       Module initialization cleanup.
 *         Ulises Alonso        :       Frame number limit removal and 
 *                                      packet_set_ring memory leak.
 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 *
 */
 
#include <linux/config.h>
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/fcntl.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/if_packet.h>
#include <linux/wireless.h>
#include <linux/kmod.h>
#include <net/ip.h>
#include <net/protocol.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <linux/errno.h>
#include <linux/timer.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/ioctls.h>
#include <linux/proc_fs.h>
#include <linux/poll.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/if_bridge.h>
 
#ifdef CONFIG_NET_DIVERT
#include <linux/divert.h>
#endif /* CONFIG_NET_DIVERT */
 
#ifdef CONFIG_INET
#include <net/inet_common.h>
#endif
 
#ifdef CONFIG_DLCI
extern int dlci_ioctl(unsigned int, void*);
#endif
 
#define CONFIG_SOCK_PACKET	1
 
/*
   Proposed replacement for SIOC{ADD,DEL}MULTI and
   IFF_PROMISC, IFF_ALLMULTI flags.
 
   It is more expensive, but I believe,
   it is really correct solution: reentereble, safe and fault tolerant.
 
   IFF_PROMISC/IFF_ALLMULTI/SIOC{ADD/DEL}MULTI are faked by keeping
   reference count and global flag, so that real status is
   (gflag|(count != 0)), so that we can use obsolete faulty interface
   not harming clever users.
 */
#define CONFIG_PACKET_MULTICAST	1
 
/*
   Assumptions:
   - if device has no dev->hard_header routine, it adds and removes ll header
     inside itself. In this case ll header is invisible outside of device,
     but higher levels still should reserve dev->hard_header_len.
     Some devices are enough clever to reallocate skb, when header
     will not fit to reserved space (tunnel), another ones are silly
     (PPP).
   - packet socket receives packets with pulled ll header,
     so that SOCK_RAW should push it back.
 
On receive:
-----------
 
Incoming, dev->hard_header!=NULL
   mac.raw -> ll header
   data    -> data
 
Outgoing, dev->hard_header!=NULL
   mac.raw -> ll header
   data    -> ll header
 
Incoming, dev->hard_header==NULL
   mac.raw -> UNKNOWN position. It is very likely, that it points to ll header.
              PPP makes it, that is wrong, because introduce assymetry
	      between rx and tx paths.
   data    -> data
 
Outgoing, dev->hard_header==NULL
   mac.raw -> data. ll header is still not built!
   data    -> data
 
Resume
  If dev->hard_header==NULL we are unlikely to restore sensible ll header.
 
 
On transmit:
------------
 
dev->hard_header != NULL
   mac.raw -> ll header
   data    -> ll header
 
dev->hard_header == NULL (ll header is added by device, we cannot control it)
   mac.raw -> data
   data -> data
 
   We should set nh.raw on output to correct posistion,
   packet classifier depends on it.
 */
 
/* List of all packet sockets. */
static struct sock * packet_sklist;
static rwlock_t packet_sklist_lock = RW_LOCK_UNLOCKED;
 
atomic_t packet_socks_nr;
 
 
/* Private packet socket structures. */
 
#ifdef CONFIG_PACKET_MULTICAST
struct packet_mclist
{
	struct packet_mclist	*next;
	int			ifindex;
	int			count;
	unsigned short		type;
	unsigned short		alen;
	unsigned char		addr[8];
};
#endif
#ifdef CONFIG_PACKET_MMAP
static int packet_set_ring(struct sock *sk, struct tpacket_req *req, int closing);
#endif
 
static void packet_flush_mclist(struct sock *sk);
 
struct packet_opt
{
	struct tpacket_stats	stats;
#ifdef CONFIG_PACKET_MMAP
	unsigned long		*pg_vec;
	unsigned int		head;
	unsigned int            frames_per_block;
	unsigned int		frame_size;
	unsigned int		frame_max;
	int			copy_thresh;
#endif
	struct packet_type	prot_hook;
	spinlock_t		bind_lock;
	char			running;	/* prot_hook is attached*/
	int			ifindex;	/* bound device		*/
#ifdef CONFIG_PACKET_MULTICAST
	struct packet_mclist	*mclist;
#endif
#ifdef CONFIG_PACKET_MMAP
	atomic_t		mapped;
	unsigned int		pg_vec_order;
	unsigned int		pg_vec_pages;
	unsigned int		pg_vec_len;
#endif
};
 
#ifdef CONFIG_PACKET_MMAP
 
static inline unsigned long packet_lookup_frame(struct packet_opt *po, unsigned int position)
{
	unsigned int pg_vec_pos, frame_offset;
	unsigned long frame;
 
	pg_vec_pos = position / po->frames_per_block;
	frame_offset = position % po->frames_per_block;
 
	frame = (unsigned long) (po->pg_vec[pg_vec_pos] + (frame_offset * po->frame_size));
 
	return frame;
}
#endif
 
void packet_sock_destruct(struct sock *sk)
{
	BUG_TRAP(atomic_read(&sk->rmem_alloc)==0);
	BUG_TRAP(atomic_read(&sk->wmem_alloc)==0);
 
	if (!sk->dead) {
		printk("Attempt to release alive packet socket: %p\n", sk);
		return;
	}
 
	if (sk->protinfo.destruct_hook)
		kfree(sk->protinfo.destruct_hook);
	atomic_dec(&packet_socks_nr);
#ifdef PACKET_REFCNT_DEBUG
	printk(KERN_DEBUG "PACKET socket %p is free, %d are alive\n", sk, atomic_read(&packet_socks_nr));
#endif
	MOD_DEC_USE_COUNT;
}
 
 
extern struct proto_ops packet_ops;
 
#ifdef CONFIG_SOCK_PACKET
extern struct proto_ops packet_ops_spkt;
 
static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,  struct packet_type *pt)
{
	struct sock *sk;
	struct sockaddr_pkt *spkt;
 
	/*
	 *	When we registered the protocol we saved the socket in the data
	 *	field for just this event.
	 */
 
	sk = (struct sock *) pt->data;
 
	/*
	 *	Yank back the headers [hope the device set this
	 *	right or kerboom...]
	 *
	 *	Incoming packets have ll header pulled,
	 *	push it back.
	 *
	 *	For outgoing ones skb->data == skb->mac.raw
	 *	so that this procedure is noop.
	 */
 
	if (skb->pkt_type == PACKET_LOOPBACK)
		goto out;
 
	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
		goto oom;
 
	spkt = (struct sockaddr_pkt*)skb->cb;
 
	skb_push(skb, skb->data-skb->mac.raw);
 
	/*
	 *	The SOCK_PACKET socket receives _all_ frames.
	 */
 
	spkt->spkt_family = dev->type;
	strncpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
	spkt->spkt_protocol = skb->protocol;
 
	/*
	 *	Charge the memory to the socket. This is done specifically
	 *	to prevent sockets using all the memory up.
	 */
 
	if (sock_queue_rcv_skb(sk,skb) == 0)
		return 0;
 
out:
	kfree_skb(skb);
oom:
	return 0;
}
 
 
/*
 *	Output a raw packet to a device layer. This bypasses all the other
 *	protocol layers and you must therefore supply it with a complete frame
 */
 
static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg, int len,
			       struct scm_cookie *scm)
{
	struct sock *sk = sock->sk;
	struct sockaddr_pkt *saddr=(struct sockaddr_pkt *)msg->msg_name;
	struct sk_buff *skb;
	struct net_device *dev;
	unsigned short proto=0;
	int err;
 
	/*
	 *	Get and verify the address. 
	 */
 
	if (saddr)
	{
		if (msg->msg_namelen < sizeof(struct sockaddr))
			return(-EINVAL);
		if (msg->msg_namelen==sizeof(struct sockaddr_pkt))
			proto=saddr->spkt_protocol;
	}
	else
		return(-ENOTCONN);	/* SOCK_PACKET must be sent giving an address */
 
	/*
	 *	Find the device first to size check it 
	 */
 
	saddr->spkt_device[13] = 0;
	dev = dev_get_by_name(saddr->spkt_device);
	err = -ENODEV;
	if (dev == NULL)
		goto out_unlock;
 
	/*
	 *	You may not queue a frame bigger than the mtu. This is the lowest level
	 *	raw protocol and you must do your own fragmentation at this level.
	 */
 
	err = -EMSGSIZE;
 	if(len>dev->mtu+dev->hard_header_len)
		goto out_unlock;
 
	err = -ENOBUFS;
	skb = sock_wmalloc(sk, len+dev->hard_header_len+15, 0, GFP_KERNEL);
 
	/*
	 *	If the write buffer is full, then tough. At this level the user gets to
	 *	deal with the problem - do your own algorithmic backoffs. That's far
	 *	more flexible.
	 */
 
	if (skb == NULL) 
		goto out_unlock;
 
	/*
	 *	Fill it in 
	 */
 
	/* FIXME: Save some space for broken drivers that write a
	 * hard header at transmission time by themselves. PPP is the
	 * notable one here. This should really be fixed at the driver level.
	 */
	skb_reserve(skb,(dev->hard_header_len+15)&~15);
	skb->nh.raw = skb->data;
 
	/* Try to align data part correctly */
	if (dev->hard_header) {
		skb->data -= dev->hard_header_len;
		skb->tail -= dev->hard_header_len;
		if (len < dev->hard_header_len)
			skb->nh.raw = skb->data;
	}
 
	/* Returns -EFAULT on error */
	err = memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len);
	skb->protocol = proto;
	skb->dev = dev;
	skb->priority = sk->priority;
	if (err)
		goto out_free;
 
	err = -ENETDOWN;
	if (!(dev->flags & IFF_UP))
		goto out_free;
 
	/*
	 *	Now send it
	 */
 
	dev_queue_xmit(skb);
	dev_put(dev);
	return(len);
 
out_free:
	kfree_skb(skb);
out_unlock:
	if (dev)
		dev_put(dev);
	return err;
}
#endif
 
/*
   This function makes lazy skb cloning in hope that most of packets
   are discarded by BPF.
 
   Note tricky part: we DO mangle shared skb! skb->data, skb->len
   and skb->cb are mangled. It works because (and until) packets
   falling here are owned by current CPU. Output packets are cloned
   by dev_queue_xmit_nit(), input packets are processed by net_bh
   sequencially, so that if we return skb to original state on exit,
   we will not harm anyone.
 */
 
static int packet_rcv(struct sk_buff *skb, struct net_device *dev,  struct packet_type *pt)
{
	struct sock *sk;
	struct sockaddr_ll *sll;
	struct packet_opt *po;
	u8 * skb_head = skb->data;
	int skb_len = skb->len;
#ifdef CONFIG_FILTER
	unsigned snaplen;
#endif
 
	if (skb->pkt_type == PACKET_LOOPBACK)
		goto drop;
 
	sk = (struct sock *) pt->data;
	po = sk->protinfo.af_packet;
 
	skb->dev = dev;
 
	if (dev->hard_header) {
		/* The device has an explicit notion of ll header,
		   exported to higher levels.
 
		   Otherwise, the device hides datails of it frame
		   structure, so that corresponding packet head
		   never delivered to user.
		 */
		if (sk->type != SOCK_DGRAM)
			skb_push(skb, skb->data - skb->mac.raw);
		else if (skb->pkt_type == PACKET_OUTGOING) {
			/* Special case: outgoing packets have ll header at head */
			skb_pull(skb, skb->nh.raw - skb->data);
		}
	}
 
#ifdef CONFIG_FILTER
	snaplen = skb->len;
 
	if (sk->filter) {
		unsigned res = snaplen;
		struct sk_filter *filter;
 
		bh_lock_sock(sk);
		if ((filter = sk->filter) != NULL)
			res = sk_run_filter(skb, sk->filter->insns, sk->filter->len);
		bh_unlock_sock(sk);
 
		if (res == 0)
			goto drop_n_restore;
		if (snaplen > res)
			snaplen = res;
	}
#endif /* CONFIG_FILTER */
 
	if (atomic_read(&sk->rmem_alloc) + skb->truesize >= (unsigned)sk->rcvbuf)
		goto drop_n_acct;
 
	if (skb_shared(skb)) {
		struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
		if (nskb == NULL)
			goto drop_n_acct;
 
		if (skb_head != skb->data) {
			skb->data = skb_head;
			skb->len = skb_len;
		}
		kfree_skb(skb);
		skb = nskb;
	}
 
	sll = (struct sockaddr_ll*)skb->cb;
	sll->sll_family = AF_PACKET;
	sll->sll_hatype = dev->type;
	sll->sll_protocol = skb->protocol;
	sll->sll_pkttype = skb->pkt_type;
	sll->sll_ifindex = dev->ifindex;
	sll->sll_halen = 0;
 
	if (dev->hard_header_parse)
		sll->sll_halen = dev->hard_header_parse(skb, sll->sll_addr);
 
#ifdef CONFIG_FILTER
	if (pskb_trim(skb, snaplen))
		goto drop_n_acct;
#endif
 
	skb_set_owner_r(skb, sk);
	skb->dev = NULL;
	spin_lock(&sk->receive_queue.lock);
	po->stats.tp_packets++;
	__skb_queue_tail(&sk->receive_queue, skb);
	spin_unlock(&sk->receive_queue.lock);
	sk->data_ready(sk,skb->len);
	return 0;
 
drop_n_acct:
	spin_lock(&sk->receive_queue.lock);
	po->stats.tp_drops++;
	spin_unlock(&sk->receive_queue.lock);
 
#ifdef CONFIG_FILTER
drop_n_restore:
#endif
	if (skb_head != skb->data && skb_shared(skb)) {
		skb->data = skb_head;
		skb->len = skb_len;
	}
drop:
	kfree_skb(skb);
	return 0;
}
 
#ifdef CONFIG_PACKET_MMAP
static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,  struct packet_type *pt)
{
	struct sock *sk;
	struct packet_opt *po;
	struct sockaddr_ll *sll;
	struct tpacket_hdr *h;
	u8 * skb_head = skb->data;
	int skb_len = skb->len;
	unsigned snaplen;
	unsigned long status = TP_STATUS_LOSING|TP_STATUS_USER;
	unsigned short macoff, netoff;
	struct sk_buff *copy_skb = NULL;
 
	if (skb->pkt_type == PACKET_LOOPBACK)
		goto drop;
 
	sk = (struct sock *) pt->data;
	po = sk->protinfo.af_packet;
 
	if (dev->hard_header) {
		if (sk->type != SOCK_DGRAM)
			skb_push(skb, skb->data - skb->mac.raw);
		else if (skb->pkt_type == PACKET_OUTGOING) {
			/* Special case: outgoing packets have ll header at head */
			skb_pull(skb, skb->nh.raw - skb->data);
			if (skb->ip_summed == CHECKSUM_HW)
				status |= TP_STATUS_CSUMNOTREADY;
		}
	}
 
	snaplen = skb->len;
 
#ifdef CONFIG_FILTER
	if (sk->filter) {
		unsigned res = snaplen;
		struct sk_filter *filter;
 
		bh_lock_sock(sk);
		if ((filter = sk->filter) != NULL)
			res = sk_run_filter(skb, sk->filter->insns, sk->filter->len);
		bh_unlock_sock(sk);
 
		if (res == 0)
			goto drop_n_restore;
		if (snaplen > res)
			snaplen = res;
	}
#endif
 
	if (sk->type == SOCK_DGRAM) {
		macoff = netoff = TPACKET_ALIGN(TPACKET_HDRLEN) + 16;
	} else {
		unsigned maclen = skb->nh.raw - skb->data;
		netoff = TPACKET_ALIGN(TPACKET_HDRLEN + (maclen < 16 ? 16 : maclen));
		macoff = netoff - maclen;
	}
 
	if (macoff + snaplen > po->frame_size) {
		if (po->copy_thresh &&
		    atomic_read(&sk->rmem_alloc) + skb->truesize < (unsigned)sk->rcvbuf) {
			if (skb_shared(skb)) {
				copy_skb = skb_clone(skb, GFP_ATOMIC);
			} else {
				copy_skb = skb_get(skb);
				skb_head = skb->data;
			}
			if (copy_skb)
				skb_set_owner_r(copy_skb, sk);
		}
		snaplen = po->frame_size - macoff;
		if ((int)snaplen < 0)
			snaplen = 0;
	}
	if (snaplen > skb->len-skb->data_len)
		snaplen = skb->len-skb->data_len;
 
	spin_lock(&sk->receive_queue.lock);
	h = (struct tpacket_hdr *)packet_lookup_frame(po, po->head);
 
	if (h->tp_status)
		goto ring_is_full;
	po->head = po->head != po->frame_max ? po->head+1 : 0;
	po->stats.tp_packets++;
	if (copy_skb) {
		status |= TP_STATUS_COPY;
		__skb_queue_tail(&sk->receive_queue, copy_skb);
	}
	if (!po->stats.tp_drops)
		status &= ~TP_STATUS_LOSING;
	spin_unlock(&sk->receive_queue.lock);
 
	memcpy((u8*)h + macoff, skb->data, snaplen);
 
	h->tp_len = skb->len;
	h->tp_snaplen = snaplen;
	h->tp_mac = macoff;
	h->tp_net = netoff;
	h->tp_sec = skb->stamp.tv_sec;
	h->tp_usec = skb->stamp.tv_usec;
 
	sll = (struct sockaddr_ll*)((u8*)h + TPACKET_ALIGN(sizeof(*h)));
	sll->sll_halen = 0;
	if (dev->hard_header_parse)
		sll->sll_halen = dev->hard_header_parse(skb, sll->sll_addr);
	sll->sll_family = AF_PACKET;
	sll->sll_hatype = dev->type;
	sll->sll_protocol = skb->protocol;
	sll->sll_pkttype = skb->pkt_type;
	sll->sll_ifindex = dev->ifindex;
 
	h->tp_status = status;
	mb();
 
	{
		struct page *p_start, *p_end;
		u8 *h_end = (u8 *)h + macoff + snaplen - 1;
 
		p_start = virt_to_page(h);
		p_end = virt_to_page(h_end);
		while (p_start <= p_end) {
			flush_dcache_page(p_start);
			p_start++;
		}
	}
 
	sk->data_ready(sk, 0);
 
drop_n_restore:
	if (skb_head != skb->data && skb_shared(skb)) {
		skb->data = skb_head;
		skb->len = skb_len;
	}
drop:
        kfree_skb(skb);
	return 0;
 
ring_is_full:
	po->stats.tp_drops++;
	spin_unlock(&sk->receive_queue.lock);
 
	sk->data_ready(sk, 0);
	if (copy_skb)
		kfree_skb(copy_skb);
	goto drop_n_restore;
}
 
#endif
 
 
static int packet_sendmsg(struct socket *sock, struct msghdr *msg, int len,
			  struct scm_cookie *scm)
{
	struct sock *sk = sock->sk;
	struct sockaddr_ll *saddr=(struct sockaddr_ll *)msg->msg_name;
	struct sk_buff *skb;
	struct net_device *dev;
	unsigned short proto;
	unsigned char *addr;
	int ifindex, err, reserve = 0;
 
	/*
	 *	Get and verify the address. 
	 */
 
	if (saddr == NULL) {
		ifindex	= sk->protinfo.af_packet->ifindex;
		proto	= sk->num;
		addr	= NULL;
	} else {
		err = -EINVAL;
		if (msg->msg_namelen < sizeof(struct sockaddr_ll))
			goto out;
		ifindex	= saddr->sll_ifindex;
		proto	= saddr->sll_protocol;
		addr	= saddr->sll_addr;
	}
 
 
	dev = dev_get_by_index(ifindex);
	err = -ENXIO;
	if (dev == NULL)
		goto out_unlock;
	if (sock->type == SOCK_RAW)
		reserve = dev->hard_header_len;
 
	err = -EMSGSIZE;
	if (len > dev->mtu+reserve)
		goto out_unlock;
 
	skb = sock_alloc_send_skb(sk, len+dev->hard_header_len+15, 
				msg->msg_flags & MSG_DONTWAIT, &err);
	if (skb==NULL)
		goto out_unlock;
 
	skb_reserve(skb, (dev->hard_header_len+15)&~15);
	skb->nh.raw = skb->data;
 
	if (dev->hard_header) {
		int res;
		err = -EINVAL;
		res = dev->hard_header(skb, dev, ntohs(proto), addr, NULL, len);
		if (sock->type != SOCK_DGRAM) {
			skb->tail = skb->data;
			skb->len = 0;
		} else if (res < 0)
			goto out_free;
	}
 
	/* Returns -EFAULT on error */
	err = memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len);
	if (err)
		goto out_free;
 
	skb->protocol = proto;
	skb->dev = dev;
	skb->priority = sk->priority;
 
	err = -ENETDOWN;
	if (!(dev->flags & IFF_UP))
		goto out_free;
 
	/*
	 *	Now send it
	 */
 
	err = dev_queue_xmit(skb);
	if (err > 0 && (err = net_xmit_errno(err)) != 0)
		goto out_unlock;
 
	dev_put(dev);
 
	return(len);
 
out_free:
	kfree_skb(skb);
out_unlock:
	if (dev)
		dev_put(dev);
out:
	return err;
}
 
/*
 *	Close a PACKET socket. This is fairly simple. We immediately go
 *	to 'closed' state and remove our protocol entry in the device list.
 */
 
static int packet_release(struct socket *sock)
{
	struct sock *sk = sock->sk;
	struct sock **skp;
 
	if (!sk)
		return 0;
 
	write_lock_bh(&packet_sklist_lock);
	for (skp = &packet_sklist; *skp; skp = &(*skp)->next) {
		if (*skp == sk) {
			*skp = sk->next;
			__sock_put(sk);
			break;
		}
	}
	write_unlock_bh(&packet_sklist_lock);
 
	/*
	 *	Unhook packet receive handler.
	 */
 
	if (sk->protinfo.af_packet->running) {
		/*
		 *	Remove the protocol hook
		 */
		dev_remove_pack(&sk->protinfo.af_packet->prot_hook);
		sk->protinfo.af_packet->running = 0;
		__sock_put(sk);
	}
 
#ifdef CONFIG_PACKET_MULTICAST
	packet_flush_mclist(sk);
#endif
 
#ifdef CONFIG_PACKET_MMAP
	if (sk->protinfo.af_packet->pg_vec) {
		struct tpacket_req req;
		memset(&req, 0, sizeof(req));
		packet_set_ring(sk, &req, 1);
	}
#endif
 
	/*
	 *	Now the socket is dead. No more input will appear.
	 */
 
	sock_orphan(sk);
	sock->sk = NULL;
 
	/* Purge queues */
 
	skb_queue_purge(&sk->receive_queue);
 
	sock_put(sk);
	return 0;
}
 
/*
 *	Attach a packet hook.
 */
 
static int packet_do_bind(struct sock *sk, struct net_device *dev, int protocol)
{
	/*
	 *	Detach an existing hook if present.
	 */
 
	lock_sock(sk);
 
	spin_lock(&sk->protinfo.af_packet->bind_lock);
	if (sk->protinfo.af_packet->running) {
		dev_remove_pack(&sk->protinfo.af_packet->prot_hook);
		__sock_put(sk);
		sk->protinfo.af_packet->running = 0;
	}
 
	sk->num = protocol;
	sk->protinfo.af_packet->prot_hook.type = protocol;
	sk->protinfo.af_packet->prot_hook.dev = dev;
 
	sk->protinfo.af_packet->ifindex = dev ? dev->ifindex : 0;
 
	if (protocol == 0)
		goto out_unlock;
 
	if (dev) {
		if (dev->flags&IFF_UP) {
			dev_add_pack(&sk->protinfo.af_packet->prot_hook);
			sock_hold(sk);
			sk->protinfo.af_packet->running = 1;
		} else {
			sk->err = ENETDOWN;
			if (!sk->dead)
				sk->error_report(sk);
		}
	} else {
		dev_add_pack(&sk->protinfo.af_packet->prot_hook);
		sock_hold(sk);
		sk->protinfo.af_packet->running = 1;
	}
 
out_unlock:
	spin_unlock(&sk->protinfo.af_packet->bind_lock);
	release_sock(sk);
	return 0;
}
 
/*
 *	Bind a packet socket to a device
 */
 
#ifdef CONFIG_SOCK_PACKET
 
static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr, int addr_len)
{
	struct sock *sk=sock->sk;
	char name[15];
	struct net_device *dev;
	int err = -ENODEV;
 
	/*
	 *	Check legality
	 */
 
	if(addr_len!=sizeof(struct sockaddr))
		return -EINVAL;
	strncpy(name,uaddr->sa_data,14);
	name[14]=0;
 
	dev = dev_get_by_name(name);
	if (dev) {
		err = packet_do_bind(sk, dev, sk->num);
		dev_put(dev);
	}
	return err;
}
#endif
 
static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
{
	struct sockaddr_ll *sll = (struct sockaddr_ll*)uaddr;
	struct sock *sk=sock->sk;
	struct net_device *dev = NULL;
	int err;
 
 
	/*
	 *	Check legality
	 */
 
	if (addr_len < sizeof(struct sockaddr_ll))
		return -EINVAL;
	if (sll->sll_family != AF_PACKET)
		return -EINVAL;
 
	if (sll->sll_ifindex) {
		err = -ENODEV;
		dev = dev_get_by_index(sll->sll_ifindex);
		if (dev == NULL)
			goto out;
	}
	err = packet_do_bind(sk, dev, sll->sll_protocol ? : sk->num);
	if (dev)
		dev_put(dev);
 
out:
	return err;
}
 
 
/*
 *	Create a packet of type SOCK_PACKET. 
 */
 
static int packet_create(struct socket *sock, int protocol)
{
	struct sock *sk;
	int err;
 
	if (!capable(CAP_NET_RAW))
		return -EPERM;
	if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW
#ifdef CONFIG_SOCK_PACKET
	    && sock->type != SOCK_PACKET
#endif
	    )
		return -ESOCKTNOSUPPORT;
 
	sock->state = SS_UNCONNECTED;
	MOD_INC_USE_COUNT;
 
	err = -ENOBUFS;
	sk = sk_alloc(PF_PACKET, GFP_KERNEL, 1);
	if (sk == NULL)
		goto out;
 
	sock->ops = &packet_ops;
#ifdef CONFIG_SOCK_PACKET
	if (sock->type == SOCK_PACKET)
		sock->ops = &packet_ops_spkt;
#endif
	sock_init_data(sock,sk);
 
	sk->protinfo.af_packet = kmalloc(sizeof(struct packet_opt), GFP_KERNEL);
	if (sk->protinfo.af_packet == NULL)
		goto out_free;
	memset(sk->protinfo.af_packet, 0, sizeof(struct packet_opt));
	sk->family = PF_PACKET;
	sk->num = protocol;
 
	sk->destruct = packet_sock_destruct;
	atomic_inc(&packet_socks_nr);
 
	/*
	 *	Attach a protocol block
	 */
 
	spin_lock_init(&sk->protinfo.af_packet->bind_lock);
	sk->protinfo.af_packet->prot_hook.func = packet_rcv;
#ifdef CONFIG_SOCK_PACKET
	if (sock->type == SOCK_PACKET)
		sk->protinfo.af_packet->prot_hook.func = packet_rcv_spkt;
#endif
	sk->protinfo.af_packet->prot_hook.data = (void *)sk;
 
	if (protocol) {
		sk->protinfo.af_packet->prot_hook.type = protocol;
		dev_add_pack(&sk->protinfo.af_packet->prot_hook);
		sock_hold(sk);
		sk->protinfo.af_packet->running = 1;
	}
 
	write_lock_bh(&packet_sklist_lock);
	sk->next = packet_sklist;
	packet_sklist = sk;
	sock_hold(sk);
	write_unlock_bh(&packet_sklist_lock);
	return(0);
 
out_free:
	sk_free(sk);
out:
	MOD_DEC_USE_COUNT;
	return err;
}
 
/*
 *	Pull a packet from our receive queue and hand it to the user.
 *	If necessary we block.
 */
 
static int packet_recvmsg(struct socket *sock, struct msghdr *msg, int len,
			  int flags, struct scm_cookie *scm)
{
	struct sock *sk = sock->sk;
	struct sk_buff *skb;
	int copied, err;
 
	err = -EINVAL;
	if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC))
		goto out;
 
#if 0
	/* What error should we return now? EUNATTACH? */
	if (sk->protinfo.af_packet->ifindex < 0)
		return -ENODEV;
#endif
 
	/*
	 *	If the address length field is there to be filled in, we fill
	 *	it in now.
	 */
 
	if (sock->type == SOCK_PACKET)
		msg->msg_namelen = sizeof(struct sockaddr_pkt);
	else
		msg->msg_namelen = sizeof(struct sockaddr_ll);
 
	/*
	 *	Call the generic datagram receiver. This handles all sorts
	 *	of horrible races and re-entrancy so we can forget about it
	 *	in the protocol layers.
	 *
	 *	Now it will return ENETDOWN, if device have just gone down,
	 *	but then it will block.
	 */
 
	skb=skb_recv_datagram(sk,flags,flags&MSG_DONTWAIT,&err);
 
	/*
	 *	An error occurred so return it. Because skb_recv_datagram() 
	 *	handles the blocking we don't see and worry about blocking
	 *	retries.
	 */
 
	if(skb==NULL)
		goto out;
 
	/*
	 *	You lose any data beyond the buffer you gave. If it worries a
	 *	user program they can ask the device for its MTU anyway.
	 */
 
	copied = skb->len;
	if (copied > len)
	{
		copied=len;
		msg->msg_flags|=MSG_TRUNC;
	}
 
	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
	if (err)
		goto out_free;
 
	sock_recv_timestamp(msg, sk, skb);
 
	if (msg->msg_name)
		memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
 
	/*
	 *	Free or return the buffer as appropriate. Again this
	 *	hides all the races and re-entrancy issues from us.
	 */
	err = (flags&MSG_TRUNC) ? skb->len : copied;
 
out_free:
	skb_free_datagram(sk, skb);
out:
	return err;
}
 
#ifdef CONFIG_SOCK_PACKET
static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
			       int *uaddr_len, int peer)
{
	struct net_device *dev;
	struct sock *sk	= sock->sk;
 
	if (peer)
		return -EOPNOTSUPP;
 
	uaddr->sa_family = AF_PACKET;
	dev = dev_get_by_index(sk->protinfo.af_packet->ifindex);
	if (dev) {
		strncpy(uaddr->sa_data, dev->name, 15);
		dev_put(dev);
	} else
		memset(uaddr->sa_data, 0, 14);
	*uaddr_len = sizeof(*uaddr);
 
	return 0;
}
#endif
 
static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
			  int *uaddr_len, int peer)
{
	struct net_device *dev;
	struct sock *sk = sock->sk;
	struct sockaddr_ll *sll = (struct sockaddr_ll*)uaddr;
 
	if (peer)
		return -EOPNOTSUPP;
 
	sll->sll_family = AF_PACKET;
	sll->sll_ifindex = sk->protinfo.af_packet->ifindex;
	sll->sll_protocol = sk->num;
	dev = dev_get_by_index(sk->protinfo.af_packet->ifindex);
	if (dev) {
		sll->sll_hatype = dev->type;
		sll->sll_halen = dev->addr_len;
		memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
		dev_put(dev);
	} else {
		sll->sll_hatype = 0;	/* Bad: we have no ARPHRD_UNSPEC */
		sll->sll_halen = 0;
	}
	*uaddr_len = sizeof(*sll);
 
	return 0;
}
 
#ifdef CONFIG_PACKET_MULTICAST
static void packet_dev_mc(struct net_device *dev, struct packet_mclist *i, int what)
{
	switch (i->type) {
	case PACKET_MR_MULTICAST:
		if (what > 0)
			dev_mc_add(dev, i->addr, i->alen, 0);
		else
			dev_mc_delete(dev, i->addr, i->alen, 0);
		break;
	case PACKET_MR_PROMISC:
		dev_set_promiscuity(dev, what);
		break;
	case PACKET_MR_ALLMULTI:
		dev_set_allmulti(dev, what);
		break;
	default:;
	}
}
 
static void packet_dev_mclist(struct net_device *dev, struct packet_mclist *i, int what)
{
	for ( ; i; i=i->next) {
		if (i->ifindex == dev->ifindex)
			packet_dev_mc(dev, i, what);
	}
}
 
static int packet_mc_add(struct sock *sk, struct packet_mreq *mreq)
{
	struct packet_mclist *ml, *i;
	struct net_device *dev;
	int err;
 
	rtnl_lock();
 
	err = -ENODEV;
	dev = __dev_get_by_index(mreq->mr_ifindex);
	if (!dev)
		goto done;
 
	err = -EINVAL;
	if (mreq->mr_alen > dev->addr_len)
		goto done;
 
	err = -ENOBUFS;
	i = (struct packet_mclist *)kmalloc(sizeof(*i), GFP_KERNEL);
	if (i == NULL)
		goto done;
 
	err = 0;
	for (ml=sk->protinfo.af_packet->mclist; ml; ml=ml->next) {
		if (ml->ifindex == mreq->mr_ifindex &&
		    ml->type == mreq->mr_type &&
		    ml->alen == mreq->mr_alen &&
		    memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
			ml->count++;
			/* Free the new element ... */
			kfree(i);
			goto done;
		}
	}
 
	i->type = mreq->mr_type;
	i->ifindex = mreq->mr_ifindex;
	i->alen = mreq->mr_alen;
	memcpy(i->addr, mreq->mr_address, i->alen);
	i->count = 1;
	i->next = sk->protinfo.af_packet->mclist;
	sk->protinfo.af_packet->mclist = i;
	packet_dev_mc(dev, i, +1);
 
done:
	rtnl_unlock();
	return err;
}
 
static int packet_mc_drop(struct sock *sk, struct packet_mreq *mreq)
{
	struct packet_mclist *ml, **mlp;
 
	rtnl_lock();
 
	for (mlp=&sk->protinfo.af_packet->mclist; (ml=*mlp)!=NULL; mlp=&ml->next) {
		if (ml->ifindex == mreq->mr_ifindex &&
		    ml->type == mreq->mr_type &&
		    ml->alen == mreq->mr_alen &&
		    memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
			if (--ml->count == 0) {
				struct net_device *dev;
				*mlp = ml->next;
				dev = dev_get_by_index(ml->ifindex);
				if (dev) {
					packet_dev_mc(dev, ml, -1);
					dev_put(dev);
				}
				kfree(ml);
			}
			rtnl_unlock();
			return 0;
		}
	}
	rtnl_unlock();
	return -EADDRNOTAVAIL;
}
 
static void packet_flush_mclist(struct sock *sk)
{
	struct packet_mclist *ml;
 
	if (sk->protinfo.af_packet->mclist == NULL)
		return;
 
	rtnl_lock();
	while ((ml=sk->protinfo.af_packet->mclist) != NULL) {
		struct net_device *dev;
		sk->protinfo.af_packet->mclist = ml->next;
		if ((dev = dev_get_by_index(ml->ifindex)) != NULL) {
			packet_dev_mc(dev, ml, -1);
			dev_put(dev);
		}
		kfree(ml);
	}
	rtnl_unlock();
}
#endif
 
static int
packet_setsockopt(struct socket *sock, int level, int optname, char *optval, int optlen)
{
	struct sock *sk = sock->sk;
	int ret;
 
	if (level != SOL_PACKET)
		return -ENOPROTOOPT;
 
	switch(optname)	{
#ifdef CONFIG_PACKET_MULTICAST
	case PACKET_ADD_MEMBERSHIP:	
	case PACKET_DROP_MEMBERSHIP:
	{
		struct packet_mreq mreq;
		if (optlen<sizeof(mreq))
			return -EINVAL;
		if (copy_from_user(&mreq,optval,sizeof(mreq)))
			return -EFAULT;
		if (optname == PACKET_ADD_MEMBERSHIP)
			ret = packet_mc_add(sk, &mreq);
		else
			ret = packet_mc_drop(sk, &mreq);
		return ret;
	}
#endif
#ifdef CONFIG_PACKET_MMAP
	case PACKET_RX_RING:
	{
		struct tpacket_req req;
 
		if (optlen<sizeof(req))
			return -EINVAL;
		if (copy_from_user(&req,optval,sizeof(req)))
			return -EFAULT;
		return packet_set_ring(sk, &req, 0);
	}
	case PACKET_COPY_THRESH:
	{
		int val;
 
		if (optlen!=sizeof(val))
			return -EINVAL;
		if (copy_from_user(&val,optval,sizeof(val)))
			return -EFAULT;
 
		sk->protinfo.af_packet->copy_thresh = val;
		return 0;
	}
#endif
	default:
		return -ENOPROTOOPT;
	}
}
 
int packet_getsockopt(struct socket *sock, int level, int optname,
		      char *optval, int *optlen)
{
	int len;
	struct sock *sk = sock->sk;
 
	if (level != SOL_PACKET)
		return -ENOPROTOOPT;
 
  	if (get_user(len,optlen))
  		return -EFAULT;
 
	if (len < 0)
		return -EINVAL;
 
	switch(optname)	{
	case PACKET_STATISTICS:
	{
		struct tpacket_stats st;
 
		if (len > sizeof(struct tpacket_stats))
			len = sizeof(struct tpacket_stats);
		spin_lock_bh(&sk->receive_queue.lock);
		st = sk->protinfo.af_packet->stats;
		memset(&sk->protinfo.af_packet->stats, 0, sizeof(st));
		spin_unlock_bh(&sk->receive_queue.lock);
		st.tp_packets += st.tp_drops;
 
		if (copy_to_user(optval, &st, len))
			return -EFAULT;
		break;
	}
	default:
		return -ENOPROTOOPT;
	}
 
  	if (put_user(len, optlen))
  		return -EFAULT;
  	return 0;
}
 
 
static int packet_notifier(struct notifier_block *this, unsigned long msg, void *data)
{
	struct sock *sk;
	struct packet_opt *po;
	struct net_device *dev = (struct net_device*)data;
 
	read_lock(&packet_sklist_lock);
	for (sk = packet_sklist; sk; sk = sk->next) {
		po = sk->protinfo.af_packet;
 
		switch (msg) {
		case NETDEV_UNREGISTER:
#ifdef CONFIG_PACKET_MULTICAST
			if (po->mclist)
				packet_dev_mclist(dev, po->mclist, -1);
			// fallthrough
#endif
		case NETDEV_DOWN:
			if (dev->ifindex == po->ifindex) {
				spin_lock(&po->bind_lock);
				if (po->running) {
					dev_remove_pack(&po->prot_hook);
					__sock_put(sk);
					po->running = 0;
					sk->err = ENETDOWN;
					if (!sk->dead)
						sk->error_report(sk);
				}
				if (msg == NETDEV_UNREGISTER) {
					po->ifindex = -1;
					po->prot_hook.dev = NULL;
				}
				spin_unlock(&po->bind_lock);
			}
			break;
		case NETDEV_UP:
			spin_lock(&po->bind_lock);
			if (dev->ifindex == po->ifindex && sk->num && po->running==0) {
				dev_add_pack(&po->prot_hook);
				sock_hold(sk);
				po->running = 1;
			}
			spin_unlock(&po->bind_lock);
			break;
		}
	}
	read_unlock(&packet_sklist_lock);
	return NOTIFY_DONE;
}
 
 
static int packet_ioctl(struct socket *sock, unsigned int cmd,
			unsigned long arg)
{
	struct sock *sk = sock->sk;
 
	switch(cmd) 
	{
		case SIOCOUTQ:
		{
			int amount = atomic_read(&sk->wmem_alloc);
			return put_user(amount, (int *)arg);
		}
		case SIOCINQ:
		{
			struct sk_buff *skb;
			int amount = 0;
 
			spin_lock_bh(&sk->receive_queue.lock);
			skb = skb_peek(&sk->receive_queue);
			if (skb)
				amount = skb->len;
			spin_unlock_bh(&sk->receive_queue.lock);
			return put_user(amount, (int *)arg);
		}
		case FIOSETOWN:
		case SIOCSPGRP: {
			int pid;
			if (get_user(pid, (int *) arg))
				return -EFAULT; 
			if (current->pid != pid && current->pgrp != -pid && 
			    !capable(CAP_NET_ADMIN))
				return -EPERM;
			sk->proc = pid;
			break;
		}
		case FIOGETOWN:
		case SIOCGPGRP:
			return put_user(sk->proc, (int *)arg);
		case SIOCGSTAMP:
			if(sk->stamp.tv_sec==0)
				return -ENOENT;
			if (copy_to_user((void *)arg, &sk->stamp,
					 sizeof(struct timeval)))
				return -EFAULT;
			break;
		case SIOCGIFFLAGS:
#ifndef CONFIG_INET
		case SIOCSIFFLAGS:
#endif
		case SIOCGIFCONF:
		case SIOCGIFMETRIC:
		case SIOCSIFMETRIC:
		case SIOCGIFMEM:
		case SIOCSIFMEM:
		case SIOCGIFMTU:
		case SIOCSIFMTU:
		case SIOCSIFLINK:
		case SIOCGIFHWADDR:
		case SIOCSIFHWADDR:
		case SIOCSIFMAP:
		case SIOCGIFMAP:
		case SIOCSIFSLAVE:
		case SIOCGIFSLAVE:
		case SIOCGIFINDEX:
		case SIOCGIFNAME:
		case SIOCGIFCOUNT:
		case SIOCSIFHWBROADCAST:
			return(dev_ioctl(cmd,(void *) arg));
 
		case SIOCGIFBR:
		case SIOCSIFBR:
#if defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)
#ifdef CONFIG_INET
#ifdef CONFIG_KMOD
			if (br_ioctl_hook == NULL)
				request_module("bridge");
#endif
			if (br_ioctl_hook != NULL)
				return br_ioctl_hook(arg);
#endif
#endif				
			return -ENOPKG;
 
		case SIOCGIFDIVERT:
		case SIOCSIFDIVERT:
#ifdef CONFIG_NET_DIVERT
			return divert_ioctl(cmd, (struct divert_cf *) arg);
#else
			return -ENOPKG;
#endif /* CONFIG_NET_DIVERT */
 
#ifdef CONFIG_INET
		case SIOCADDRT:
		case SIOCDELRT:
		case SIOCDARP:
		case SIOCGARP:
		case SIOCSARP:
		case SIOCGIFADDR:
		case SIOCSIFADDR:
		case SIOCGIFBRDADDR:
		case SIOCSIFBRDADDR:
		case SIOCGIFNETMASK:
		case SIOCSIFNETMASK:
		case SIOCGIFDSTADDR:
		case SIOCSIFDSTADDR:
		case SIOCSIFFLAGS:
		case SIOCADDDLCI:
		case SIOCDELDLCI:
			return inet_dgram_ops.ioctl(sock, cmd, arg);
#endif
 
		default:
			if ((cmd >= SIOCDEVPRIVATE) &&
			    (cmd <= (SIOCDEVPRIVATE + 15)))
				return(dev_ioctl(cmd,(void *) arg));
 
#ifdef CONFIG_NET_RADIO
			if((cmd >= SIOCIWFIRST) && (cmd <= SIOCIWLAST))
				return(dev_ioctl(cmd,(void *) arg));
#endif
			return -EOPNOTSUPP;
	}
	return 0;
}
 
#ifndef CONFIG_PACKET_MMAP
#define packet_mmap sock_no_mmap
#define packet_poll datagram_poll
#else
 
unsigned int packet_poll(struct file * file, struct socket *sock, poll_table *wait)
{
	struct sock *sk = sock->sk;
	struct packet_opt *po = sk->protinfo.af_packet;
	unsigned int mask = datagram_poll(file, sock, wait);
 
	spin_lock_bh(&sk->receive_queue.lock);
	if (po->pg_vec) {
		unsigned last = po->head ? po->head-1 : po->frame_max;
		struct tpacket_hdr *h;
 
		h = (struct tpacket_hdr *)packet_lookup_frame(po, last);
 
		if (h->tp_status)
			mask |= POLLIN | POLLRDNORM;
	}
	spin_unlock_bh(&sk->receive_queue.lock);
	return mask;
}
 
 
/* Dirty? Well, I still did not learn better way to account
 * for user mmaps.
 */
 
static void packet_mm_open(struct vm_area_struct *vma)
{
	struct file *file = vma->vm_file;
	struct inode *inode = file->f_dentry->d_inode;
	struct socket * sock = &inode->u.socket_i;
	struct sock *sk = sock->sk;
 
	if (sk)
		atomic_inc(&sk->protinfo.af_packet->mapped);
}
 
static void packet_mm_close(struct vm_area_struct *vma)
{
	struct file *file = vma->vm_file;
	struct inode *inode = file->f_dentry->d_inode;
	struct socket * sock = &inode->u.socket_i;
	struct sock *sk = sock->sk;
 
	if (sk)
		atomic_dec(&sk->protinfo.af_packet->mapped);
}
 
static struct vm_operations_struct packet_mmap_ops = {
	open:	packet_mm_open,
	close:	packet_mm_close,
};
 
static void free_pg_vec(unsigned long *pg_vec, unsigned order, unsigned len)
{
	int i;
 
	for (i=0; i<len; i++) {
		if (pg_vec[i]) {
			struct page *page, *pend;
 
			pend = virt_to_page(pg_vec[i] + (PAGE_SIZE << order) - 1);
			for (page = virt_to_page(pg_vec[i]); page <= pend; page++)
				ClearPageReserved(page);
			free_pages(pg_vec[i], order);
		}
	}
	kfree(pg_vec);
}
 
 
static int packet_set_ring(struct sock *sk, struct tpacket_req *req, int closing)
{
	unsigned long *pg_vec = NULL;
	struct packet_opt *po = sk->protinfo.af_packet;
	int order = 0;
	int err = 0;
 
	if (req->tp_block_nr) {
		int i, l;
 
		/* Sanity tests and some calculations */
 
		if (po->pg_vec)
			return -EBUSY;
 
		if ((int)req->tp_block_size <= 0)
			return -EINVAL;
		if (req->tp_block_size&(PAGE_SIZE-1))
			return -EINVAL;
		if (req->tp_frame_size < TPACKET_HDRLEN)
			return -EINVAL;
		if (req->tp_frame_size&(TPACKET_ALIGNMENT-1))
			return -EINVAL;
 
		po->frames_per_block = req->tp_block_size/req->tp_frame_size;
		if (po->frames_per_block <= 0)
			return -EINVAL;
		if (po->frames_per_block*req->tp_block_nr != req->tp_frame_nr)
			return -EINVAL;
		/* OK! */
 
		/* Allocate page vector */
		while ((PAGE_SIZE<<order) < req->tp_block_size)
			order++;
 
		err = -ENOMEM;
 
		pg_vec = kmalloc(req->tp_block_nr*sizeof(unsigned long*), GFP_KERNEL);
		if (pg_vec == NULL)
			goto out;
		memset(pg_vec, 0, req->tp_block_nr*sizeof(unsigned long*));
 
		for (i=0; i<req->tp_block_nr; i++) {
			struct page *page, *pend;
			pg_vec[i] = __get_free_pages(GFP_KERNEL, order);
			if (!pg_vec[i])
				goto out_free_pgvec;
			memset((void *)(pg_vec[i]), 0, PAGE_SIZE << order);
			pend = virt_to_page(pg_vec[i] + (PAGE_SIZE << order) - 1);
			for (page = virt_to_page(pg_vec[i]); page <= pend; page++)
				SetPageReserved(page);
		}
		/* Page vector is allocated */
 
		l = 0;
		for (i=0; i<req->tp_block_nr; i++) {
			unsigned long ptr = pg_vec[i];
			struct tpacket_hdr *header;
			int k;
 
			for (k=0; k<po->frames_per_block; k++) {
 
				header = (struct tpacket_hdr*)ptr;
				header->tp_status = TP_STATUS_KERNEL;
				ptr += req->tp_frame_size;
			}
		}
		/* Done */
	} else {
		if (req->tp_frame_nr)
			return -EINVAL;
	}
 
	lock_sock(sk);
 
	/* Detach socket from network */
	spin_lock(&po->bind_lock);
	if (po->running)
		dev_remove_pack(&po->prot_hook);
	spin_unlock(&po->bind_lock);
 
	err = -EBUSY;
	if (closing || atomic_read(&po->mapped) == 0) {
		err = 0;
#define XC(a, b) ({ __typeof__ ((a)) __t; __t = (a); (a) = (b); __t; })
 
		spin_lock_bh(&sk->receive_queue.lock);
		pg_vec = XC(po->pg_vec, pg_vec);
		po->frame_max = req->tp_frame_nr-1;
		po->head = 0;
		po->frame_size = req->tp_frame_size;
		spin_unlock_bh(&sk->receive_queue.lock);
 
		order = XC(po->pg_vec_order, order);
		req->tp_block_nr = XC(po->pg_vec_len, req->tp_block_nr);
 
		po->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
		po->prot_hook.func = po->pg_vec ? tpacket_rcv : packet_rcv;
		skb_queue_purge(&sk->receive_queue);
#undef XC
		if (atomic_read(&po->mapped))
			printk(KERN_DEBUG "packet_mmap: vma is busy: %d\n", atomic_read(&po->mapped));
	}
 
	spin_lock(&po->bind_lock);
	if (po->running)
		dev_add_pack(&po->prot_hook);
	spin_unlock(&po->bind_lock);
 
	release_sock(sk);
 
out_free_pgvec:
	if (pg_vec)
		free_pg_vec(pg_vec, order, req->tp_block_nr);
out:
	return err;
}
 
static int packet_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
{
	struct sock *sk = sock->sk;
	struct packet_opt *po = sk->protinfo.af_packet;
	unsigned long size;
	unsigned long start;
	int err = -EINVAL;
	int i;
 
	if (vma->vm_pgoff)
		return -EINVAL;
 
	size = vma->vm_end - vma->vm_start;
 
	lock_sock(sk);
	if (po->pg_vec == NULL)
		goto out;
	if (size != po->pg_vec_len*po->pg_vec_pages*PAGE_SIZE)
		goto out;
 
	atomic_inc(&po->mapped);
	start = vma->vm_start;
	err = -EAGAIN;
	for (i=0; i<po->pg_vec_len; i++) {
		if (remap_page_range(start, __pa(po->pg_vec[i]),
				     po->pg_vec_pages*PAGE_SIZE,
				     vma->vm_page_prot))
			goto out;
		start += po->pg_vec_pages*PAGE_SIZE;
	}
	vma->vm_ops = &packet_mmap_ops;
	err = 0;
 
out:
	release_sock(sk);
	return err;
}
#endif
 
 
#ifdef CONFIG_SOCK_PACKET
struct proto_ops packet_ops_spkt = {
	family:		PF_PACKET,
 
	release:	packet_release,
	bind:		packet_bind_spkt,
	connect:	sock_no_connect,
	socketpair:	sock_no_socketpair,
	accept:		sock_no_accept,
	getname:	packet_getname_spkt,
	poll:		datagram_poll,
	ioctl:		packet_ioctl,
	listen:		sock_no_listen,
	shutdown:	sock_no_shutdown,
	setsockopt:	sock_no_setsockopt,
	getsockopt:	sock_no_getsockopt,
	sendmsg:	packet_sendmsg_spkt,
	recvmsg:	packet_recvmsg,
	mmap:		sock_no_mmap,
	sendpage:	sock_no_sendpage,
};
#endif
 
struct proto_ops packet_ops = {
	family:		PF_PACKET,
 
	release:	packet_release,
	bind:		packet_bind,
	connect:	sock_no_connect,
	socketpair:	sock_no_socketpair,
	accept:		sock_no_accept,
	getname:	packet_getname, 
	poll:		packet_poll,
	ioctl:		packet_ioctl,
	listen:		sock_no_listen,
	shutdown:	sock_no_shutdown,
	setsockopt:	packet_setsockopt,
	getsockopt:	packet_getsockopt,
	sendmsg:	packet_sendmsg,
	recvmsg:	packet_recvmsg,
	mmap:		packet_mmap,
	sendpage:	sock_no_sendpage,
};
 
static struct net_proto_family packet_family_ops = {
	family:		PF_PACKET,
	create:		packet_create,
};
 
static struct notifier_block packet_netdev_notifier = {
	notifier_call:	packet_notifier,
};
 
#ifdef CONFIG_PROC_FS
static int packet_read_proc(char *buffer, char **start, off_t offset,
			     int length, int *eof, void *data)
{
	off_t pos=0;
	off_t begin=0;
	int len=0;
	struct sock *s;
 
	len+= sprintf(buffer,"sk       RefCnt Type Proto  Iface R Rmem   User   Inode\n");
 
	read_lock(&packet_sklist_lock);
 
	for (s = packet_sklist; s; s = s->next) {
		len+=sprintf(buffer+len,"%p %-6d %-4d %04x   %-5d %1d %-6u %-6u %-6lu",
			     s,
			     atomic_read(&s->refcnt),
			     s->type,
			     ntohs(s->num),
			     s->protinfo.af_packet->ifindex,
			     s->protinfo.af_packet->running,
			     atomic_read(&s->rmem_alloc),
			     sock_i_uid(s),
			     sock_i_ino(s)
			     );
 
		buffer[len++]='\n';
 
		pos=begin+len;
		if(pos<offset) {
			len=0;
			begin=pos;
		}
		if(pos>offset+length)
			goto done;
	}
	*eof = 1;
 
done:
	read_unlock(&packet_sklist_lock);
	*start=buffer+(offset-begin);
	len-=(offset-begin);
	if(len>length)
		len=length;
	if(len<0)
		len=0;
	return len;
}
#endif
 
static void __exit packet_exit(void)
{
	remove_proc_entry("net/packet", 0);
	unregister_netdevice_notifier(&packet_netdev_notifier);
	sock_unregister(PF_PACKET);
	return;
}
 
static int __init packet_init(void)
{
	sock_register(&packet_family_ops);
	register_netdevice_notifier(&packet_netdev_notifier);
#ifdef CONFIG_PROC_FS
	create_proc_read_entry("net/packet", 0, 0, packet_read_proc, NULL);
#endif
	return 0;
}
 
module_init(packet_init);
module_exit(packet_exit);
MODULE_LICENSE("GPL");